The health risks of smoking are well known and yet people continue to smoke. One contributing factor may be that smokers can enjoy the reinforcing properties of cigarettes in the present, whereas they may view loosing their health as occurring in the distant future, if it occurs at all. Such a viewpoint can be classified as impulsive or showing little self-control, because the small, immediate, certain reward (cigarettes) is viewed as being more valuable than the substantially larger, delayed, uncertain reward (being healthy in 10 years). A series of experiments is proposed that asks: (1) whether smokers do in fact discount the value of future, uncertain events relative to the value of future, uncertain events relative to the value of immediate events; and (2) what factors influence this discounting. Study I will assess whether moderate smokers choose immediate, certain money over delayed, uncertain money more frequently than nonsmokers. Study II will assess whether nicotine abstinence (24 hours versus none) increase the value of cigarettes, relative to delayed, uncertain monetary rewards, as indicated by increased preference for immediate, certain cigarettes over delayed, uncertain money. Study III will examine whether providing substitutes for cigarettes can reduce the immediate value of smoking relative to the delayed, uncertain monetary rewards, using three commodities that vary in their substitutability for cigarettes (nonpreferred brand cigarettes, chewing gum and postage stamps). Study IV will use moderate and light smokers to compare the sensitivity of cigarette preference over delayed, uncertain rewards with the sensitivity of smokers to increases in cigarette price (elasticity of demand). Taken together these four studies will improve our understanding of the factors influencing cigarette smoking and, in a larger context, the factors involved in assessing the value of immediate, certain versus future, uncertain rewards.